The invention relates to an apparatus for turning up tire side walls on a shaping drum for the shaping of a tire carcass.
An apparatus of said type is presented for example in DE 103 00 969 A1. Said apparatus has two core clamping devices for receiving in each case one bead core, two turn-over devices with a multiplicity of spreadable fingers or levers, and a spindle arrangement for the synchronous axial movement of the core clamping devices in opposite directions and for the synchronous axial movement of the turn-over devices in opposite directions independently of the core clamping devices. The spindle arrangement has a central spindle for driving the turn-over devices and has a hollow spindle, mounted on the central spindle, for the actuation of the core clamping devices. The spindles can be connected to one another by way of a coupling and can be driven by way of a motor that acts on the central spindle. The design of the hollow spindle and the coaxial mounting of the spindles however necessitate high outlay in terms of manufacture and apparatus.
The European patent EP 2 217 433 B1 presents a turn-over apparatus for tire side walls, the spindle arrangement of which has a spindle pair with two parallel spindles. One spindle drives core clamping devices, and the other spindle drives turn-over devices. Said turn-up apparatus duly dispenses with a hollow spindle and is thus, from a manufacturing aspect, simpler to manufacture than the above-described turn-up apparatus according to DE 103 00 969 A1, but the sliding forces imparted by the spindles are not introduced symmetrically into the core clamping devices and the turn-over devices. As a result, it is possible for the respective bead cores to become orientated obliquely with respect to one another, which, during the shaping process, yields an uneven elevation of the tire carcass and thus uneven contact with the respective belt pack. This can result in the tires exhibiting a non-uniform mass distribution. Furthermore, the asymmetrical introduction of force results in high reaction forces being exerted on the shaping drum by the core clamping devices and by the turn-over devices, resulting in increased wear and a short service life.